Double action safety switch



1943- .1. H. BRETTHAUER ETAL 2,326,199

DOUBLE ACTION SAFETY SWITCH Filed Dec. 6, 1940 2 Sheets-Sheet l Ei J QlASl/ZAT/OA so 2915 13 10 JOHN HERMANBRETTHAUER WILLIAM CERMAK IN VENTORS ATTORNE Y 1943- J. H. BRETTHAUER ETAL 2,326,199-

DOUBLE ACTION SAFETY SWITCH Filed Dec. 6, 1940 2 Sheets-Sheet 2 JOHNHERMAN BRETTHAUER 0 WILLIAM G ERMAK INVENTORS WWW ATTORNEY Patented Aug.10, 1943 7 DOUBLE ACTION SAFETY SWITCH John Herman Bretthauer andWilliam New York, N. Y.

Applicazion December 6, 1940, Serial No. 368,960

Claims.

This invention relates to safety switches used in circuits wherein abatten is charged by a generator.

"Themain obiect of this invention is to provide adouble-aictlon safetyswitch which will protect All the electriwl equipment in such circuits.

Another obiectrcf this invention is to provide a safety having anangularly shaped armature and to mount the said armature at one endthereof While the other end cmtects bhcks forming th termmations ofcontact carrying arms so as to cause an increase in the pressure betweenthe contact points when the armature is being pulled down due to anexcess voltage in the generator above normal.

' Another objeotof this invention is to provide a combinedcircuit-opening and circuit-closing induction type switch having twoelectromagnets, one of which is adapted to draw down the armature whenthere is an excess voltage produced in the generator due to a loose or(men 0011- nectionin the battery circuit, and the other electromagnet isadapted to draw down the armature when there is a short circuit in thecircult, such as that used in automobiles.

Another object 01' this invention is to provide a combined switch havingtwo independently acting electromegnets and two sets of successivelybreaking contact points, one set for the lighting circuit and the otherset for the generator field circuit, and to so arrange the breaking ofthe contact points that the contact points for the lighting circuit willbreak before breaking the contacts for the generator field circuit.

With the above and other objects in view, the invention will behereinafter more particularly described, and the combination andarrangement of parts will be shown in the accompanying drawings andpointed out in the claims which form part of this specification.

Reference will now be had to the drawings, wherein like numerals ofreference designate corresponding parts throughout the several views, inwhich:

Figure 1 is a plan view the invention. 7

Figure 2 is a front elevational view of the switch shown in Figure 1,without the fuses and electric lamp shown in Figure 1.

Figure 3 is a fragmentary section on line of 8-4, Figure 1.

Figure 4 is a. diagrammatic representation of the elements of theinvention and their electrical connection as applied .to circuitswherein of a switch embodying lights are shown in conjunction with abattery and generator.

Figure 5 is a fragmentary view of the switch, partly broken away, toshow a control devic .for raising or lowering the armature.

In the illustrated embodiment of the invention, the numeral 1D indicatesa double-action safety induction type switch comprising an armature Hwhich has been hinged at. llfto one end of an angularlyshapedloracket l3fixed to the upper surface of an insulating base-plate M by screws 15.

'Ihebracket l3 has'fbeen positioned to provide an upright extension 13forming a magnetic leg with which the armature tends to complete themagnetic circuit when elec'tromagne'ts are energ'hed. I

The armature H has an aperture ll permitting passage therefliroug'h ofa. hook l8 which is integral with the extension Jli and acts asa stopand limits the upward movement of the armature II. An electromagnet I9serving as a voltage control, has an iron core 20, the lower end ofwhich has been fixed to the horizontal leg of the bracket l3. g

The iron core 21) has been wound with insulated copper wire having anumber of turns to magnetize the core and be adapted to pull down thearmature against the resistance of springs and blocks which normallymaintain the armature in contact with the stop I8 and away from contactwith the extension 16. Under operating conditions, when the armature Hcontacts the extension 16, there is a clearance between the lowersurface of the armature and the top of the iron core 20. s p

A pull spring 2| has been secured to the baseplate [4 by a screw 28. Ascrew 22 has been threaded in insulating material 23'secured by screws Mto the upper surface of the armature II. The screw 22 passes through anoval shaped clearance hole (not shown) in the pull spring 2! and servesas a means for azfiusting the tension of the spring 21 and causing a,constantly acting pull on the armature. The spring 2| pulls the armatureaway from the upper surface of the extension 16, and tends to bring thearmature up to the upper stop l8.

As best shown in Figure 2, a contact 25 has been fixed to the pullspring 21. A contact 28 is carried by a spring arm 21, The spring 21 hasbeen secured to the base-plate II by a screw 29. Normally thecontactslfi and 26 are in separated relation and control an auxiliarycircuit,

:control a primary circuit.

and the armature H is in spaced relation from the extension I 5.

A spring arm 23% carrying a contact 3.! has been fixed to the base-plateIt by a screw A spring arm 34 carrying a contact 32 has been fixed tothe base-plate M by a screw 35. Normally, thecontacts 3| and 32 arein'contacting relation, and control a primary circuit.

As shown in Figure 3, a spring arm it carry-.

ing a contact ll has been fixed to the base-plate Mby a screw 63.

by a screw 55. It is to be noted that the contacts ii and 3-2 arepositioned rearwardly of the contacts iil and 32. Normally, the contactsll and 32 are are also in contacting position by screws as and so in thespring arms 38 and Ail." Asbes t shown in Figure 2, the bottom'surfacesof the blocks 56, and M are in-sub stantially horizontal planes.

It is to be noted that the bottom surface of the block All is above thebottom surface of the block 35. This arrangement of the blocks 55 and 41is forthe purpose of releasing block tl relation, and V a A spring arm Q3 carrying a a contact 42 has been fixed to the base-plate i ii and 2.As best shown in Figure 2, the electromagnets l9 and 59 are mounted onthe bracket iii in spaced-apart relation.

Operation of invention As shown in Figure 4, the double action safetyswitch iii is in circuit with and serves to protect electric lights 65.A voltage'control and/ or a currentccntrol (not shown) may be in seriesWith the generatorfield circuit to the ground 66. The generator 61 isgrounded.

For the purpose of the invention there has been provided auxiliary oremergency lights E53 and an auxiliary battery 83. An indicator light E8in circuit with the auxiliary'battery'ta serves to vis- I ually signalto the operator that there is a loose or broken connection in thecircuit of the storage before releasing block 48 and in order to breakthe contacts M and iz befo're breaking the con.-

tacts 3i and 32.

Under operating conditions the contact points l-l and 2 are in serieswith the lighting circuit; while the'contact points 3i and 32 are inseries with the generator field circult, 1 The prior breaking of thecontact points 4] and 42 protectsthe electric lights from burning out,as is the case when'there isa loose'or broken connectionfin thebattery'circuit'fl As shown in Figure 2,it will be seenothat' the aabove the horizontal plane, that is, the upper leg of the armature makesan obtuse angle with the upright leg. This angular positionof the upperleg of the armature functions so' that'when the armature H is normallyangularly positioned movementinc reases the pressure onthe contactpoints to take care of the overload onthe points s: and and ii and whichwould be due to 5.,

a'loose connection in the battery circuit. Itis 'to be noted that incase of an open circuit in the An electromagnet 59 serving a shortcircuit i control has an. iron core 6l3, the lower end of which hasbeen'fixed to the horizontal leg of the bracket it. The ironcore (it hasbeen "wound with insulated copper wireof heavier gauge than the'wire on'the electromagnet Hip-The winding on the core 69 servesto magnetizethesaid core so as to bealso adapted to pull down'thearmae ture againstthe resistance of the spring 2 and the blocks; {it and 41. It isto benoted that 7 during the time the electromagnet 59 pulls down thearmature H there will be the same increase in pressure on the contactpoints 3| and 32, and

'batteryt l, or'that fuse l2 has been burnt out due to a short circuitin one of the primary circuits." r is T -An indicator light iiinparallel shunt with the short circuit electromagnet 59 serves tovisually signal to' the operator that there is a short circuit. Theindicator light ll lights only when fuse i3 burns'out. The fuse To isdestroyed by excessive temperature caused by abnormal electricalconditions such as excessive current flow. I Cur-' rentffrom the batteryis now automatically diverted' to "the electromagnet E9 Whichbecomes fuly energized and'powerf-ul enoughto pull down the armature ll. The fuse72 serves toprotect theelectric-lightste while fuse 73 serves to protectthe'ammeter i i, and-thegenerator 61, and other circuits connectedthereto'in the event of a short circuit or in the event that thegenerator cutout i9 fails tc'break the'c'ircuit. i

' The circuits shoWn may comprise an ignition fuse l5; it, a heater fuseTi, and a horn fuse l8.

In the event that any onebfthese fuses it to 78 inclusiveburn out; thecircuit of the switch it may'not be effected because these fuses have asmaller carryin capacity than the fuse numbered'lS. V i V I VRegardless-of which electrometgnet is ch -59 causes the armature to bedrawn to theextension iii of the bracketlB, the contact-s ll and d2break'prior to'the breaking'of the contacts 3! and 32. This arrangementserves to first break the light circuit'before breaking the fieldcircuit.

It is to be noted that the friction pressure blocks it-and il provide apredetermined tension against downward movement of the armasure. down byone ofthe electromagnets, the block 5 holds the armature down so as tocause contacts 3i and 32, and ll and 42 to-stay open, andtc'keepcontacts 25 and 267 closed.

The screw 22 maybe adjusted so as to increase or decrease the pull ofthe spring El on the armature from the extension-l6 so as to insure themaintenance of thefarr'nature against the upper stop it unde normalconditions: In the event of an increase of voltage in the generatorabove normal, the. pull from the electromagnet le'will overcome thetension of the spring 2i J and pull the armature down to trip the blocks48 and 47.

a It isto be noted that the electromagnet I9 is connected incircuituwith thegenerator 5'8 and will operate only when the generatoris in oper ation. When the armature trips the-blocksfi and' i'i, theupper surface of the armature comes 7. below the lower surface of' theblock as; The block at then holds the armature down. Due

to the movement of the block 46 over the arma- When the armature hasbeen drawn ments at the free end of the armature.

ture, the field circuit of tbe generator is broken and the electromagnetI9 is demagnetioed.

When both indicator lights "and H are bum ing, it indicates that fuse I3is burnt out. If light I9 only bums it indicates a loose connection oropen circuit or a burnt out fuse n.

For the purpcse'of raising the armature H to the normal operating shownin Figures 2 and 5 after the armature was pulleddown, we have provided alever 80 made of flat spring metal fulcrumed at 81 and hem a cam-shapedmember 82 which is normally out of contact with the blocks and with thearmature l I.

When it is desired to raise thearmature after being pulled down, theoperator moves the lever 80 towards the blocks 46 and 41, and thecamshaped member 82 moves the blocks to the right and permits the spring2| to raise the armature up to normal operating position.

When it i desired to close the circuit to the auxiliary lights, theoperator can move the lever 80 to the left and cause the cam-shapedmember 82 to press down the armature and releas the blocks to permitsaid blocks to move above the upper surface of the armature and to holdthe armature down.v

It is to be noted that due to the manner of hinging the armature II atits lower end l2 that there are both horizontal and vertical move- Thesecombined movements facilitate the downward motion of the armature to theelectromagnets.

It is also to be noted that when there is a leak in a storage batterycell or the electrolyte becomes low, the resistance in the batterycircuit would increase and allow the generator voltage to rise, therebyincreasing the energy of the electroinagnet l9 and causing the armatureH to be attracted toward the electromagnet and break the light and fieldcircuits and close the auxiliary light circuit.

In the application of our invention to the protection of electricalequipment including auxiliary and main light circuits, We may provide asingle two-circuit combination switch (not shown) to control both lightcircuits simultaneously.

It will thus be seen that this invention is adapted to protect all theelectrical appliances that are generally used in circuits wherein abattery isbeing charged by a generator, and appliances in electricalcircuits in general.

In accordance with the patent statutes we have described and illustratedthe preferred embodiment of our invention, but it will be understoodthat various changes and modifications can be made therein withoutdeparting from the spirit of the invention as defined by the appendedclaims.

It will thus be seen that there has been provided an electro-magneticsafety switch wherein a plurality of primary circuits having contacts3l-32, and H 42, which are normally closed, are successively opened.Also, that a normally open auxiliary circuit having contacts 2'526 is'closed after one set cf primary circuit contacts are broken.

We claim:

1. A device of the character described comrig in combination a magnetcoil, an L- aped armature lever having one end pivoted adjacent the baseof said coil whereby its free end has a movement in response to saidcoil having both a horizontal and a vertical componcnt and beingspring-pressed away from said coil, a pair of switches mounted adiacmtto said free end each having a movable member carrying a block, saidmember being toaward said armature end and in a direction to open saidswitch, each block having a horizon tal and a vertical face of suchdimensions that when the vertical faces are engaged by said free end,bot/h swiwhes are held closed and when said free end comes beneath thehorizontal faces both switches are released to open and said lever isnew by one of said faces inmagnet operated one of said horizontal facesbeing higher than the other, whereby one switch is opened before theother.

2. A device of the character described com prising in combination amagnet coil, an L- shaped armature lever having one end pivoted adjacentthe base of said coil whereby its free end has a movement in response tosaid coil having both a horizontal and a vertical component and beingspring-pressed away from said coil, a pair of switches mounted adjacentto said free end each having a movable member carrying a block, saidmember being spring-pressed toward said armature and in a direction toopen said switch, each block having a horizontal and a vertical face ofsuch dimensions that when the vertical faces are engaged by said freeend, both switches are held closed and when said free end comes beneaththe horizontal faces both switches are released to open and said leveris held by one of said faces in magnet operated position, and a manualreleasing member movable to engage said switch members to cause saidblocks to disengage said horizontal faces from said armature lever andhaving a member for engaging said lever to depress the same on movementof said releasing member in the other direction, to release said switchmembers.

3. A device of the character described comprising in combination amagnet coil, an L- shaped armature lever having one end pivoted adjacentthe base of said coil whereby its free end has a movement in response tosaid coil having both a horizontal and a vertical component and beingspring-pressed away from said coil, a pair of switches mounted adjacentto said free end each having a movable member carrying a block, saidmember being spring-pressed toward said armature end in a direction toopen said switch, each block having a horizontal and a vertical face ofsuch dimensions that when the vertical faces are engaged by said freeend, both switches are held closed and when said free end comes beneaththe horizontal faces both switches are released to open and said leveris held by one of said faces in magnet operated position, the armatureand switch members being so constructed and arranged that as saidarmature is moved toward its operated position, it increases thepressure on said vertical faces to increase the pressure of contact ofsaid springs, until it passes beneath said horizonta1 faces.

4. A device of the character described comprising in combination, amagnet coil, an armature lever pivoted adjacent said coil and springpressed away from said coil, a pair of switches mounted adjacent thefree end of the armature each having a movable member carrying a block,said member being spring pressed toward said armature end and in adirection to open the switch, each block having a face inclined to thedirection of movement of the end of the armature whereby the movement ofthe armature may closesaid switch and a horizontal face, the

dimensions of said block being suchthat when I the armature passes belowthe horizontalfaces it is held down, one of said horizontal faces beinghigher than the other whereby as saidarmature is actuated one of, saidswitches will open before the other. V

- 5. A device of the character described comprising in combination, amagnet coil, an armae ture lever pivoted adjacent said coil and springpressed away from said coil, a pair of switches mounted adjacentthe freeendof the armature each having a movable member carrying a block,

1 said member being spring pressed toward said "armatu'reqend and in adirection to open the t JOHN BRETTHAUER.

WILLIAM CERMAK. Q

